1. Field of the Invention
The present invention relates to a ball seat valve. More specifically, the present invention relates to a ball seat valve configured so as to reduce or prevent pressure pulsations in the volume flow of the medium flowing out of the chamber of the ball seat valve and to reduce the pressure between the in flowing medium outside and inside the chamber
2. Description of the Related Art
One example of a prior art ball seat valve is shown in FIG. 3 in a lateral cross section view and a plan view. The ball seat valve has a valve body 1 with a chamber 2 into which four large inlet openings 3* lead through a cover-like wall. A seat 4 with an outlet opening 6 is formed in the wall of the valve body 1 opposite the inlet openings 3*, with the outlet opening leading out of the chamber 2 through the valve body 1. A ball 5 is situated in the chamber 2 such that it can be displaced to open up or block the outlet opening 6. A flexible element 8 forces the ball 5 into a normal position in which it blocks the outlet opening 6 in the seat 4 by pre-stressing the ball 5 against the outlet opening 6 from a side opposite the outlet opening 6. The ball 5 can be forced out of the seat 4 in the opposite direction, against the force of the flexible element 8, by a tappet 9, which can be inserted from the opposite side through the outlet opening 6 so as to open up the outlet opening 6.
The dimensions of the inlet openings 3* are such that each opening has a flow-through inflow area A1* leading into the chamber 2 that is larger than a flow-through outflow area A2 of the outlet opening 6.
The total inflow area ΣA1* of all the inlet openings 3* is consequently very large as compared with the flow-through outflow area A2 of the outlet opening 6. When a medium M having a high and potentially pulsating external pressure p1 flows up to the inlet openings 3*, it enters the chamber 2 through the inlet openings 3*, and then exits the same through the outlet opening 6 when outlet opening 6 is open. Because each of the inlet openings 3* has a large inflow area A1* as compared with the outflow area A2 of the outlet opening 6, a chamber pressure p2* is created during the flow through the chamber 2, which is approximately equal to the external pressure p1.
The volume flow Q* exiting after flowing through a ball seat valve of this type is heavily dependent upon the initial pressure that prevails in the chamber 2 as chamber pressure p2*. Based upon the initial pressure, the valve is highly sensitive to pressure pulses with high pressure frequencies. Pressure pulses initially cause a rapid increase in flow rate. After a short time, however, the ball 5 is forced into the seat 4 by the increased flow or volume flow Q* of the flowing medium M. The operating point becomes unstable because the ball-closing forces fluctuate while the ball-opening forces, which act on the ball 5 via the tappet 9, remain the same.
As a result, the chamber pressure p2* prevailing in the conventional chamber 2 is essentially equal to the external pressure p1, as is illustrated in FIG. 4. This diagram shows pressure pulses ip2* having a clearly identifiable amplitude or intensity I, recurring over time t. These cause corresponding fluctuations in a curve illustrating volume flow Q*, shown at the bottom, which indicates corresponding flow-through pulses or fluctuations, each comprising an intensity increase followed by an intensity decrease in the volume flow Q*.
Accordingly, there is a need for an improved ball seat valve wherein: the structure is less sensitive to pressure pulses; where a more uniform flow of the medium is provided; where there is an elimination of sensitivity of the ball to a bumping of the seat, resulting in a decrease in wear and tear; and, there is a filter effect, which keeps particles of dirt from reaching the interior of the valve.